1. Field of the Invention
This invention relates to a lens refractivity measuring apparatus for use in an ophthalmologic clinic, an optician's shop or the like.
2. Related Background Art
In a conventional lens refractivity measuring apparatus when the refractive power of a progressive multifocal lens is to be measured, a mark is attached to a positioning sheet or the like prepared for each kind of lens in order to take aim at a position to be measured, and the measurement of refractive power at a far viewing position or a near viewing position is effected with the optical axis of the apparatus adjusted to this mark. Therefore, much time is required for the measurement of a progressive multifocal lens. Also, there is known a lens refractivity measuring apparatus in which whether the measuring optical axis is on a progressive zone is displayed when the additional power of a progressive multifocal lens is measured, but since the additional may vary in the progressive zone, it is difficult to judge where the measurement should be done.